The monitor got installed in the boat the following weekend, and it worked perfectly. Sort of. Not really. When exposed to direct sunlight, a frequent occurrence where it’s installed, the screen fogged up so as to completely obscure the display.

Clearly this is a case of moisture contamination so off the boat and back to the bench. I opened up the casing, which I deemed unnecessary in the first pass but clearly I had to go a little deeper. I was hoping to find lots of high density foam rubber like what you see everything mounted in inside of a Panasonic tough book. That would provide an easy scapegoat for where the moisture was hiding, but alas, everything inside was solidly constructed with no obvious antivibration/impact mountings. But no matter, the moisture had to be hiding in there somewhere. The guts was all in a single assembly with the screen backlight and mainboard all attached and rigidly assembled. Sandwiched between the casing halves and secured with the same screws, with none of the dangling boards and parts secured with tape you normally run into when you strip the screen out of a monitor.

I grabbed a folded blanket out of the cupboard and put the screen assembly in the middle of the stack with a remote probe thermometer underneath it. I put heating pad about five layers lower and turned it on low. An evening of twiddling with the distance between the heating pad and the screen while watching TV got the assemblie safely holding at the target temperature.

Although I didn’t have specifications for the parts in question I assume that the screen itself was the most heat sensitive component and did a little googling. Determining that 120°F to 130°F would be nice safe maximum storage temperature for the screen.

I left that to cook for 48 hours and performed a few more tweaks to the casing. The stripped screw on one of the cover panels on the back got passed over on the first run through as unnecessary, I feel differently about it now. The closest larger screw I had on hand was #6 course so I drilled and tapped the stripped hole to fit.

The day night toggle switch on the bottom had a crack in its rubber boot, the day night function wasn’t really necessary as the software provides the same functionality so I eliminated the switch and sealed the hole with a stainless steel screw and a rubber washer.

The monitor has been back in service for a couple weeks now and the fogging problem has not returned. Perhaps in future we will all be wary of moisture problems in electronics that has spent significant time in someone’s basement.

Probably should’ve taken a picture that, oh well, you can’t think of everything.

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